A large-curved cross-material high-load landing impact support structure

Abstract

A large curved surface cross-material high-load landing impact support structure belongs to the field of spacecraft structure technology, including an outer curved wall panel, an inner diagonal brace plate, a floor, a reinforcing stringer, a main joint angle box, and lower and upper diagonal brace angle boxes. The outer curved wall panel is fixedly connected to the inner diagonal brace plate through the inner diagonal brace connection angle box, and forms a basic load-bearing structure with the reinforcing stringer; the inner diagonal brace plate is connected to the inner connection frame of the outer curved wall panel through the three lower diagonal brace angle boxes below, and is connected to the floor through the upper diagonal brace angle box above; the reinforcing stringer is interlocked with the lower diagonal brace angle box and the upper diagonal brace angle box. A main joint angle box is set at the main joint of the landing impact load, and the main joint angle box serves as the only transmission path for the landing impact load. The landing impact load support structure of the present invention ensures that it can withstand large concentrated out-of-plane loads under basic constraints; it realizes lightweight load design from the structural configuration, realizes cross-material load bearing of large concentrated loads, and improves the diffusion efficiency of concentrated loads and the structural load-bearing capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft structures, and specifically relates to a large-curved cross-material high-load landing impact support structure, which is particularly suitable for spacecraft structures such as manned lunar landers whose main body adopts a sealed cabin structure, and can also be extended to other situations that need to withstand large concentrated loads. Background Art

[0002] When a manned lunar lander lands on the moon, it will generate a large landing impact load, which is transmitted to the main structure of the lander through the landing leg joint. The load magnitude is much greater than the load that the lander bears when flying in the active phase of the rocket. It is necessary to concentrate the force and diffuse the landing joint load and design a separate load support structure. In response to the configuration requirements of the manned lunar lander, the main structure of the manned lunar lander adopts a sealed cabin design. The outer shape is a large curved thin-walled metal wall plate reinforced configuration, and the inner layer adopts a high-rigidity carbon fiber curved inner support plate. At the same time, the weight index requirements are extremely strict. It is necessary to meet the strict lightweight index constraints on the basis of meeting the sealing, large curved configuration, cross-material and high load-bearing requirements. This puts higher requirements on the design of the landing impact load support structure. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-load-bearing landing impact load support structure design in response to the requirements of sealing, large curved surface configuration and concentrated force diffusion of cross-material landing impact loads of a manned lunar lander, which can be better suitable for bearing lunar landing impact loads or other situations that need to withstand large concentrated loads outside the surface.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A large curved cross-material high-load landing impact support structure, the landing impact load support structure includes an outer curved wall panel 1, an inner diagonal brace plate 2, a floor 3, a reinforcing truss 4, a main joint angle box 5, a lower diagonal brace angle box 6, and an upper diagonal brace angle box 7. The outer curved wall panel 1 and the inner diagonal brace plate 2 are in an oblique "T" configuration, that is, the outer curved wall panel 1 is fixedly connected to the inner diagonal brace plate 2 in an oblique "T" shape through the inner diagonal brace connection angle box, and forms a basic load-bearing structure with the reinforcing truss 4. A main joint angle box 5 is provided at the main joint of the landing impact load, and the main joint angle box 5 transfers the landing impact load to the outer curved wall panel 1, the inner diagonal brace plate 2, and the reinforcing truss 4. The overall configuration of the landing impact load support structure is basically symmetrical, and the direction of the resultant force in the landing impact load surface is basically collinear with the taper of the inner diagonal brace plate 2, thereby reducing the bending moment borne by the overall support structure.

[0006] Furthermore, a main joint angle box 5 is provided at the main joint of the landing impact load, and the main joint angle box 5 is connected to the outer curved wall panel 1 through a blind hole on the outer curved wall panel 1, serving as the only transmission path for the landing impact load. The inner diagonal brace plate 2 is connected to the connection frame inside the outer curved wall panel 1 through three lower diagonal brace angle boxes 6 at the bottom, and is connected to the floor through an upper diagonal brace angle box 7 at the top; the reinforcing beam 4 is W-shaped, and is interlocked with the lower diagonal brace angle box 6 and the upper diagonal brace angle box 7.

[0007] Furthermore, the outer wall panel structure 1 is a large curved thin-walled reinforced configuration, the ribs are a high-low rib integrated design, and the whole adopts a metal thin-walled shell. The landing impact load main joint is connected to the main joint corner box 5 by blind hole screwing and bonding. The optimized parameters include the reinforcement area and reinforcement thickness at the main joint of the wall panel. Specifically: the ribs 11 of the large curved thin-walled reinforced configuration are designed as straight orthogonal high-low ribs; the wall panel structure 12 at the main joint of the landing impact load is locally thickened and grooved for weight reduction according to the optimization results, and the thickened area and thin-walled area are transitioned by large fillets 13 to achieve strength transition of the wall panel structure.

[0008] Furthermore, the inner diagonal brace plate structure 2 is a conical carbon fiber honeycomb sandwich plate structure (the inner diagonal brace plate structure 2 adopts a honeycomb sandwich structure, which is a conical large curved surface structure according to the configuration requirements), the lower end is connected to the landing joint and other loads, and the upper end is connected to the floor structure, which improves the floor support stiffness while bearing the landing impact load. Panel reinforcement and honeycomb encryption are adopted in the landing joint load-bearing area, and the panel material is selected from the M series high modulus carbon fiber composite material. The optimized parameters include: the inner diagonal brace plate oblique cone angle, the overall thickness, the panel reinforcement area, thickness, the honeycomb reinforcement area and the honeycomb specifications. Specifically: the skin is strengthened in different regions according to the landing impact load joint connection and strength optimization, and the honeycomb encryption is performed in the connection area of ​​the reinforcement truss 4. Through the reinforcement area design, the structural weight is reduced on the basis of meeting the structural strength.

[0009] Furthermore, the main joint corner box 5 is provided with reinforcing ribs. The landing impact concentration point load is diffused and transferred to the outer curved wall panel 1 through the reinforcing ribs 51. Since the center point ribs converge, the material accumulates to form a dead weight, and the center point dead weight is hollowed out from the back, which greatly reduces the weight of the joint structure. Constrained by the configuration layout, loads P1, P2, and P3 are applied to the supporting structure through the main joint corner box 5. The maximum load is about 80kN, which far exceeds the design load of the flight section. The main joint corner box 5 bears and transmits all loads and is the only transmission path. The landing impact concentration point load is diffused more evenly to the larger elliptical area of ​​the wall panel through the oblique ribs. The main joint is made of high-strength aluminum material with a very high strength ratio, which can greatly reduce the weight of the structure while ensuring the load-bearing capacity.

[0010] Furthermore, the reinforcing truss 4 is arranged in a W-shape, with a cross-section in the shape of a Chinese character "J", and is attached to the inner support plate 2, making full use of the stiffness of the truss in the height direction to efficiently diffuse the concentrated load of the landing impact load. The optimized parameters include: the truss layout configuration, the height of the truss cross-section, and the thickness. Specifically: the reinforcing truss 4 is installed on the inner diagonal support plate 2 through the two wing end surface connection holes. At the upper and lower ends, the reinforcing truss 4, the inner diagonal support plate 2, and the upper and lower diagonal support angle boxes 6 / 7 are interlocked. In order to avoid the upper diagonal support angle box 7, a sinking avoidance structure 41 is provided above the reinforcing truss 4 for sinking avoidance.

[0011] Furthermore, the taper angle of the inner diagonal brace plate 2 is 15° to 25°, preferably 20°. Since the additional bending moments of the loads P1, P2, and P3 are borne by the outer curved wall panel and the inner diagonal brace plate, by optimizing the taper angle of the inner diagonal brace plate, the load direction under the maximum load condition of landing impact is in the same linear direction as the diagonal brace angle of the inner diagonal brace plate, thereby maximizing the reduction of the additional bending moment to be borne by the supporting structure, and maximizing the lightweight design of the additional bending moment load from the structural configuration.

[0012] Furthermore, the dimensional design requirements for each structure are as follows:

[0013] The overall thickness of the outer wall panel structure 1 is only 1.2mm to 1.5mm. The wall panel is thickened to 15mm at the main joint of the landing impact load. The area is an elliptical area with a height of 200mm and a length of 300mm. It is connected to the main joint corner box 5 by gluing and screwing. Under the constraints of manned sealing, large curved surface configuration and processing technology, it meets the landing impact bearing strength requirements.

[0014] The honeycomb sandwich structure of the inner diagonal brace plate 2 in the cabin has an overall thickness of 15 mm. The panel material is a high modulus carbon fiber composite material different from the outer wall panel structure, with a thickness of 0.32 mm. An internal reinforcement panel reinforcement method is adopted in the landing joint bearing area, such as Figure 6 As shown, the diameters of the three reinforced areas are 150mm, 185mm, and 150mm, and the laying order is the mirror image of the adhered panel, with a thickness of 0.32mm. The internal diagonal brace plate 2 in the cabin mainly transmits the in-plane load of the body, with a honeycomb thickness of 14.7mm and a specification of 0.03mm×5mm. The honeycomb density in the main area for transmitting the landing impact load is 0.03mm×3mm.

[0015] According to the optimization results of load concentration and diffusion, four W-shaped reinforcing trusses are attached to the inner diagonal brace plate. The reinforcing trusses are in an "I" shape, 25mm high, 40mm wide, and 1.5mm thick. They are made of high modulus carbon fiber composite materials. While strengthening the stiffness and strength of the inner diagonal brace plate, the landing impact load is distributed and diffused over a large area. By selecting a high modulus carbon fiber material different from the metal material of the outer wall panel, cross-material bearing of the landing impact load is achieved.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The landing impact load support structure of the present invention can withstand large concentrated out-of-plane loads under the constraints of sealing, large curved thin-walled panels and strict weight indicators;

[0018] (2) The inner support plate described in the present invention is an oblique support cone structure, and the oblique cone angle is collinear with the landing impact load direction, which minimizes the generation of load-added bending moment and realizes load lightweight design from the perspective of structural configuration.

[0019] (3) The outer wall panels described in the present invention are made of metal materials with good sealing properties, and the inner support plates and external reinforcement beams are made of high modulus carbon fiber composite materials with good stiffness and strength, which fully utilizes the functions and mechanical properties of different materials and realizes cross-material bearing of large concentrated loads.

[0020] (4) The W-shaped reinforcing truss described in the present invention distributes and diffuses the concentrated load, and is attached to the inner support plate externally, avoiding the embedded height limit of the honeycomb panel, and can fully utilize the stiffness in the height direction, thereby greatly improving the diffusion efficiency of the concentrated load and the structural bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall assembly of the landing impact load support structure of the present invention;

[0022] Figure 2 The bottom view of the overall assembly of the landing impact load support structure of the present invention;

[0023] Figure 3 The overall assembly top view of the landing impact load support structure of the present invention (with the floor hidden);

[0024] Figure 4 It is a schematic diagram of the middle section of the landing impact load support structure of the present invention;

[0025] Figure 5 It is a schematic diagram of the outer curved wall panel of the present invention;

[0026] Figure 6 It is a schematic diagram of the reinforcement of the inner diagonal brace plate panel and the honeycomb reinforcement of the present invention;

[0027] Figure 7 Schematic diagram of the main joint corner box of the present invention with reinforcement and hollowing out the back to reduce weight; (a) front side of the main joint corner box; (b) back side of the main joint corner box

[0028] Figure 8 (a) is a schematic diagram of the shape of the reinforcing truss of the present invention; Figure 8 (b) Figure 8 (a) a cross-sectional view;

[0029] In the figure: 1 outer curved wall panel; 2 inner diagonal brace panel; 3 floor; 4 reinforcing trusses; 5 main joint corner box; 6 lower diagonal brace corner box; 7 upper diagonal brace corner box; 11 ribs; 12 wall panel structure; 13 large rounded corner; 41 sinking avoidance structure; DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0031] The landing impact load support structure provided in this embodiment has an outer curved wall panel 1 fixedly connected to the inner diagonal support panel 2 in an oblique "T" shape through a lower diagonal support angle box 6, and together with the reinforcing truss 4, it forms a basic load-bearing structure. Figure 1 , Figure 2 , Figure 3 As shown. Loads P1, P2, and P3 are applied to the main joint angle box 5, which is connected to the outer wall panel by glue screws through the blind holes on the outer wall panel 1. The inner diagonal brace is screwed to the connection frame inside the outer curved wall panel 1 through the three lower diagonal brace angle boxes 6 below, and is screwed to the floor through the upper diagonal brace angle box 7 above. The reinforcing beam 4 is W-shaped and interlocks with the lower diagonal brace angle box 6 and the upper diagonal brace angle box 7. The overall structure is basically symmetrical, as shown in FIG. Figure 4 As shown, the direction of the resultant force in the landing impact load plane is substantially collinear with the taper of the inner diagonal support plate 2, thereby reducing the bending moment borne by the overall supporting structure.

[0032] The outer wall plate structure 1 of this embodiment is a large curved thin-wall reinforced structure. Figure 5 As shown. The whole adopts a metal thin-walled shell, and the ribs 11 are designed with straight orthogonal high and low ribs. At the main joint of the landing impact load, the wall panel structure 12 is locally thickened and grooved to reduce weight according to the optimization results. The thickened area and thin-walled area are transitioned with large fillets 13 to achieve the strength transition of the wall panel structure.

[0033] The inner diagonal brace plate structure 2 of this embodiment is a conical carbon fiber honeycomb sandwich plate, and the panel reinforcement and honeycomb reinforcement are shown in the figure. Figure 6 As shown in the figure, the skin was strengthened in different regions according to the landing impact load joint connection and strength optimization, and the honeycomb encryption was carried out in the connection area of ​​the reinforced truss 4. Through the detailed design of the reinforcement area, the structural weight was reduced while meeting the structural strength.

[0034] The main joint corner box 5 of this embodiment is the only transmission path for the landing impact load and is made of high-strength aluminum 7075 material, such as Figure 7As shown, the landing impact concentrated point load is diffused and transferred to the outer curved wall panel 1 through the reinforcing ribs 51. Since the center point ribs converge, the material accumulates to form dead weight, and the center point dead weight is hollowed out from the back, which greatly reduces the weight of the joint structure.

[0035] The cross section of the reinforcing truss 4 in this embodiment is in the shape of a Chinese character "J". It is screwed on the inner diagonal brace plate 2 through the connection holes on the two wing end faces. At the upper and lower ends, the reinforcing truss 4, the inner diagonal brace plate 2, and the upper and lower diagonal brace angle boxes 6 / 7 are interlocked with each other. In order to avoid the upper diagonal brace angle box 7, a sinking avoidance structure 41 is provided above the reinforcing truss 4 to avoid sinking. Figure 8 shown.

[0036] The dimensional design requirements of each structure in this embodiment are as follows:

[0037] The overall thickness of the outer wall panel structure 1 is only 1.2mm to 1.5mm. The wall panel is thickened to 15mm at the main joint of the landing impact load. The area is an elliptical area with a height of 200mm and a length of 300mm. It is connected to the main joint corner box 5 by gluing and screwing. Under the constraints of manned sealing, large curved surface configuration and processing technology, it meets the landing impact bearing strength requirements.

[0038] The honeycomb sandwich structure of the inner diagonal brace plate 2 in the cabin has an overall thickness of 15 mm. The panel material is a high modulus carbon fiber composite material different from the outer wall panel structure, with a thickness of 0.32 mm. An internal reinforcement panel reinforcement method is adopted in the landing joint bearing area, such as Figure 6 As shown, the diameters of the three reinforced areas are 150mm, 185mm, and 150mm, and the paving order is the mirror image of the adhered panel, with a thickness of 0.32mm. The internal diagonal brace plate 2 in the cabin mainly transmits the in-plane load of the body, with a honeycomb thickness of 14.7mm and a specification of 0.03mm×5mm. The honeycomb density in the main area for transmitting the landing impact load is 0.03mm×3mm.

[0039] According to the optimization results of load concentration and diffusion, four W-shaped reinforcing trusses are attached to the inner diagonal brace plate. The reinforcing trusses are in an "I" shape, 25mm high, 40mm wide, and 1.5mm thick. They are made of high modulus carbon fiber composite materials. While strengthening the stiffness and strength of the inner diagonal brace plate, the landing impact load is distributed and diffused over a large area. By selecting a high modulus carbon fiber material different from the metal material of the outer wall panel, cross-material bearing of the landing impact load is achieved.

[0040] In this embodiment, Patran / Nastran finite element software is used to perform support structure strength analysis under landing conditions. The outer curved wall panel 1, the inner diagonal brace plate 2, the reinforcing stringer 4, and the main joint corner box 5 are simulated using shell elements (SHELL ELMENT). The analysis results of Nastran include the stress, strain and safety margin of each component. Through the optimization of the structural weight, the final design parameters are determined on the premise of meeting the safety margin specification requirements, including: the reinforcement area and reinforcement thickness at the joint of the outer curved wall panel; the diagonal brace angle of the inner diagonal brace plate 2, the ply of the panel, the area size and thickness of the reinforcing sheet; the layout and cross-sectional dimensions of the reinforcing stringer 4; the wall thickness and rib thickness of the main joint corner box 5 and other parameters.

[0041] In order to verify the effect of the landing impact load support structure, a landing impact load support structure test piece was processed, and a multi-condition identification-level static test was carried out. The test results show that the landing impact load support structure scheme described in the present invention is correct, the parameters are reasonably selected, and it can meet the landing load requirements of a manned lunar lander.

[0042] In practical applications, the material, thickness, dimensions and other parameters of the outer wall panels, inner support panels, reinforcing beams and main joint corner boxes may be adjusted according to the load bearing size and relative position, and the present invention does not make specific limitations on this.

[0043] It should be noted that the contents not described in detail in this specification can be implemented by those skilled in the art through the description in this specification and the prior art, and will not be elaborated here.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. For those skilled in the art, several modifications and replacements can be made to the present invention without paying creative work, and all these modifications and replacements should be included in the protection scope of the present invention.

Claims

1. A large curved cross-material high load-bearing landing impact load support structure, characterized in that: The landing impact load support structure comprises an outer curved wall panel (1), an inner diagonal brace panel (2), a floor panel (3), a reinforcing truss (4), a main joint angle box (5), a lower diagonal brace angle box (6), and an upper diagonal brace angle box (7); The outer curved wall panel (1) and the inner diagonal brace panel (2) are in an oblique "T" shape. The outer curved wall panel (1) is fixedly connected to the inner diagonal brace panel (2) in an oblique "T" shape through the inner diagonal brace connection angle box, and together with the reinforcing truss (4) form a basic load-bearing structure; the inner diagonal brace panel (2) is connected to the connection frame on the inner side of the outer curved wall panel (1) through three lower diagonal brace angle boxes (6) at the bottom, and is connected to the floor (3) through the upper diagonal brace angle box (7) at the top; the reinforcing truss (4) is mutually interlocked with the lower diagonal brace angle box (6) and the upper diagonal brace angle box (7); A main joint corner box (5) is provided at the main joint of the landing impact load support structure. The main joint corner box (5) is connected to the outer curved wall panel (1) through a blind hole on the outer curved wall panel (1) and serves as the only transmission path for the landing impact load, that is, the landing impact load is transmitted to the outer curved wall panel (1), the inner diagonal brace plate (2) and the reinforcing truss (4) through the main joint corner box (5); The overall configuration of the landing impact load support structure is basically symmetrical, and the direction of the resultant force in the landing impact load surface is basically colinear with the taper of the inner diagonal support plate (2), thereby reducing the bending moment borne by the overall support structure; the outer curved wall panel (1) is a large curved thin-wall reinforced configuration, the ribs are a high-low rib integrated design, and the whole adopts a metal thin-wall shell, and the main joint of the landing impact load support structure is connected to the main joint corner box (5) by blind hole screw connection and bonding.

2. The large curved surface cross-material high load-bearing landing impact support structure according to claim 1, characterized in that: The ribs (11) of the large curved thin-wall reinforced configuration are designed with straight orthogonal high and low ribs; the wall panel structure (12) located at the main joint of the landing impact load support structure is locally thickened and grooved for weight reduction according to the optimization result, and the thickened area and thin-walled area are transitioned by large fillets (13) to achieve strength transition of the wall panel structure.

3. The large curved surface cross-material high load-bearing landing impact support structure according to claim 1, characterized in that: The inner diagonal brace plate (2) is a conical carbon fiber honeycomb sandwich plate structure, the lower end of which is connected to the landing joint, and the upper end of which is connected to the floor (3) structure, so as to increase the supporting stiffness of the floor (3) while bearing the landing impact load; the inner diagonal brace plate (2) is optimized by panel reinforcement and honeycomb encryption in the landing joint bearing area, wherein the panel material is selected from carbon fiber composite materials.

4. The large curved surface cross-material high load-bearing landing impact support structure according to claim 3, characterized in that: The skin is reinforced in different regions according to the landing impact load joint connection and strength optimization, and the honeycomb density is performed in the connection area of ​​the reinforced truss (4). Through the reinforcement area design, the structural weight is reduced while meeting the structural strength.

5. The large curved surface cross-material high load-bearing landing impact support structure according to claim 1, characterized in that: The main joint corner box (5) is provided with reinforcing ribs (51); the landing impact concentration point load is diffused and transferred to the outer curved wall panel (1) through the reinforcing ribs (51); the main joint corner box (5) is used to bear and transfer all loads and is the only transfer path, and the landing impact concentration point load is diffused more evenly to a large elliptical area of ​​the wall panel through the oblique ribs.

6. The large curved surface cross-material high load-bearing landing impact support structure according to claim 5, characterized in that: The main joint corner box (5) is made of high-strength aluminum material.

7. The large curved surface cross-material high load-bearing landing impact support structure according to claim 1, characterized in that: The described reinforcing girder (4) is arranged in a W shape, with a channel-shaped cross-section, and is externally attached to the inner diagonal bracing plate (2); specifically: the reinforcing girder (4) is installed on the inner diagonal bracing plate (2) through the wing end connection holes. At the upper and lower ends, the reinforcing girder (4), the inner diagonal bracing plate (2), and the upper and lower diagonal bracing angle boxes (6) / 7 are mutually engaged. To avoid the upper diagonal bracing angle box (7), a sinking avoidance structure (41) is provided above the reinforcing girder (4) for sinking avoidance.

8. The large curved surface cross-material high load-bearing landing impact support structure according to claim 1, characterized in that: The oblique cone angle of the described inner diagonal bracing plate (2) is 15° to 25°.

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